The characteristic feature of brown algae is the presence of ..........

Hydrocolloids are obtained from red algae and brown algae,respectively,as:

The antibiotic "chlorellin" is extracted from which genus?

Select the correct option by matching Column-$I$ with Column-$II$.

Column-$I$	Column-$II$
$(A)$ Blue-green algae	$(p)$ Chlamydomonas
$(B)$ Unicellular algae	$(q)$ Spirogyra
$(C)$ Filamentous algae	$(r)$ Volvox
$(D)$ Colonial algae	$(s)$ Nostoc

Agar is commercially obtained from $..........$.

Which of the following statements are applicable to brown algae?
$(I)$ They contain pigments like chlorophyll $a$,chlorophyll $c$,carotenoids,and xanthophylls.
$(II)$ They vary in color from olive green to various shades of brown.
$(III)$ Food is stored as complex carbohydrates,in the form of laminarin or mannitol.
$(IV)$ The cell wall is composed of cellulose and algin.
$(V)$ The cell wall is covered on the outside by a gelatinous coating of algin.